Detecting muscles with electromyography

The folks at Advancer Technologies just release a muscle sensor board with a great walk through posted on Instructables describing how this board measures the flexing of muscles using electromyography.

Using the same electrode placement points as the remote controlled hand we covered earlier, the muscle is measured by sensing the voltage between the muscle and its tendon. The result is a fairly fine-grained sensing of the output – more than enough to provide some analog control for a project.

The board itself is relatively simple – an INA106 differential amp is used to sense if a muscle is flexing or not. This signal is then amplified and rectified, after which it can be connected to the analog input of your favorite microcontroller. The video demo shows the board connected to a Processing app running from an Arduino, but it wouldn’t be hard to adapt this towards remote Nerf sentry turret controlled by your biceps.

Check out the video after the break to see the muscle sensor board in action.

This tech has been used for powered exoskeleton (see: http://www.youtube.com/watch?v=-UpxsrlLbpU ) research since at least 2004. It’s come a long way since then, but honestly I find the advances in prosthetic limbs more exciting. We’re talking arms and legs controlled by thought–the user moves his “phantom limb” and the prosthetic moves. The newest ones even allow for some degree of tactile feedback.

Ironically, prosthetic tech is about as much driven by the military as the exoskeleton research: many of the test subjects are servicemen/women who lost limbs in combat.